Weft tension control for loom shuttles



May 15, 1951 R. G. TURNER 2,553,221

WEF T TENSION CONTROL FOR LOOM SHUTTLES Filed 061',- 20, 1949 INVENTOR RIOHA-RD e. TURNER ATTORNEY Patented May 15, 1951 WEFT TENSION CONTROL FOR LOOM SHUTTLES Richard G. Turner, Worcester, Mass., assignor to Crompton & Knowles Loom Works, Worcester, Mass., a corporation of Massachusetts Application October 20, 1949, Serial No. 122,495

Claims. (Cl. 139-217) This invention relates to improvements in weft tension means for loom shuttles and it is the general object of the invention to provide means for controlling the Weft tension pads in such manner that they will not cut the weft when there is a sudden change in the acceleration of the shuttle, as when it is checked at the end of its flight, or is set in motion at the beginning of its flight.

Many self-threading shuttles for weft replenishing looms employ two friction pads on opposite sides of the thread passage which extends through the threader block of the shuttle. These pads are loosely mounted and are spring urged toward each other to maintain tension on the weft which passes between them while the shuttle is in flight. Because of the fact that the pads are loosely mounted they can move relatively to each other in such manner as to pinch or cut the weft whenever there is an abrupt change in the acceleration of the shuttle. The acceleration referred to herein may be either an increase or a decrease in the speed of the shuttle.

It is an important object of the present invention to provide the shuttle with means which effects a slight separation of the tension pads when the aforesaid change in the acceleration of the shuttle occurs, thereby preventing the pads from pinching or cutting the weft thread.

It is a further object of the invention to provide means mounted for limited free motion on the shuttle effective due to its inertia or momentum, depending upon whether the shuttle is being moved at the start of a picking operation, or is being checked near the end of its flight, to spread the tension pads slightly so that even though the pads should move angularly their edges, which might otherwise contact each other, will be held apart sufficiently to be unable to cut the weft thread.

It is a still further object of the invention to provide the shuttle block with means mounted at the lower ends of the tension pads for limited free motion relatively to the shuttle and having pins or the like which move against the pads to separate them incident to a sudden change in the acceleration of the shuttle.

t is another object of the invention to pro vide a guard to prevent the weft from engaging and becoming entangled with the aforesaid pins. The guard will be above the tops of the pins and may conveniently be the guide rod which supports the pads, but this feature of the invention is not limited to the guide rod.

With these and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawings, wherein a convenient embodiment of the invention is set forth,

Fig. 1 i a plan view of one end of a shuttle having the invention applied thereto,

Fig. 2 is an enlarged vertical transverse cross section on line 22, Fig. 1.

Fig. 3 is a horizontal section on line 33, Fig. 2, showing the spreader member and tension pads in normal position.

Fig. 4 is an enlarged diagrammatic view of the tension pads in normal position as shown in Fig. 3,

Fig. 5 is a view similarto Fig. 4 but showing the tension pads separated due to movement of the spreader member when the shuttle is suddenly stopped in its flight, and

Fig. 6 is a perspective view of the spreader member.

Referring particularly to Fig. 1, the shuttle SI carries a bobbin B the Weft W of which unwinds from the bobbin and passes through a thread passage in formed in the threader block II when the shuttle is in flight. The threader block has mounted thereon two vertically extending tension members or pads l3 and M which are located respectively in front of and behind the weft thread. The lower end of each pad is formed with an opening l5 which fits loosely on a support pin or guide rod 16 held by the threader block and extending horizontally across the thread passage It]. The upper end of each pad may be formed with a lateral extension or finger I! which fits into an opening lain the threader block. The fingers ll do not fully occupy their opening is and permit some freedom of motion of the pads relatively to the threader block ll.

Each pad is urged toward the other by a light compression spring 20 which may be backed up by an adjusting screw 2| threaded into the block I I, and each pad is provided with a substantially fiat vertical weft engaging surface 22 along which the thread moves horizontally or longitudinally of the shuttle and thread passage In to the delivery eye E when the shuttle is in flight.

As will be understood from Fig. 2, the extension or finger I! of each pad is located at one side of a vertical line passing through the corresponding flat weft engaging surface 22, and when there is an abrupt change in the acceleration of the shuttle, as when it is checked near the end of its flight, the fingers I! by reason of their momentum produce slight rocking or angular movements of the pads relatively to each oth r flanges and their pads define vertical edges arranged in pairs, one'pair toward the bobbin B and the other toward the delivery eye E. :The

aforesaid angular movements of the pads occur around one or the other of these pairs of edges, and it is the latter which tend to cut' the weft.

The matter thus far described is of usual construction and operates as already set forth. The springs 23 which urge the pads toward each other are not sufiiciently'strong to prevent the previously described relative angular motion of the pads or their tendency to cut the weft.

In carrying the present invention into effect simple means are provided adjacent to the lower ends of the tension pads to effect their separation at the very time in the flight of the shuttle when the pads tend to move angularly and cut the weft. This means as set forth herein includes a spreader or separator S, shown more particularly in Fig. 6, having a base or plate 33 which may be made from a piece of flat sheet metal having upstanding therefrom separator or operator pins, these pins being designated at 3| and 32. As shown in Fig. 4, pin 3| is on the side of the tension'pads adjacent to the bobbin, while the other pin 32 is on the opposite side of the pads. The plate 33 and the pins 3| and 32 are aligned lengthwise of the shuttle passage ID.

The base has a limited sliding motion in the direction of the length of the shuttle on a sur- 7 face 33 formed on the shuttle. This surface as set forth in Fig. 2 is on the Wood part of the shuttle, but it is not necessarily thus located, and it will be sufiicient if any part of the shuttle provides a supporting surface along which the plate or block 3!! can slide or move in a direction lengthwise of the shuttle.

Under normal conditions when the shuttle is either in full flight or is at rest with respect to the lay the pins 3| and 32 will be in such position as not to interfere with the action of the springs 20 in holding the pads in their normal weft tensioning position. When an abrupt change occurs in the acceleration of the shuttle, as when it is checked at the end of a flight, the spreader S, being free to move on surface 33 in the direction of the length of the shuttle, will because of its momentum move toward the leading end of the shuttle and in doing so will force One or the other of the pins 3| or 32 between the lower ends of the tension pads a sufficient distance to separate the latter so that even'though they should rock as already set forth their edges 25 will be held spaced from the weft thread, or

at least be prevented from exerting suflicient force on the thread tocut it. This operation of the .spreader means S occurs at the end of every flight of the shuttle without regard to'th'e direction in which it is traveling, and occurs at'the same time the pads tend to move angularly. It

also occurs at the beginning of a shuttle picking operation.

As shown in Fig. 5, it is assumed that the h shuttle has been traveling in the direction of arrow a and when suddenly brought to rest the spreader S moves so that pin 3| is in the 'posi- 4 tion shown. Restoration of the spreader to its normal non-spreading position with respect to the pads is facilitated by reason of the inclined flanges 23 and 24 on the pads. The springs 20 cooperate with these flanges of the pads to move one or the other of the pins 3| or 32 back to its normal position, depending upon which pin has been movedbetween the pads upon shuttle stoppage. The inclined surfaces 35 and 36 form edges 31 with their respective Weft engaging surfaces -22, and-itis these edges which tend to cut the weft when the pads have the aforesaid angular movements.

It is to be understood that when the shuttle is in normal flight the weft will traverse a path through the thread passage H) which is directed generallydownwardly and toward the delivery eye E of the thread block I I so that even though the upper ends of the pads may be in direct engagement with each other when the shuttle is suddenly checked, the lower"parts of the pads would otherwise cut the '-weft threads.

will be out of engagement due to location of one or the other of the pins 3| and 32 between the pads and the 'weft will escape pinching or cutting as the pads rock.

As clearly shown in Fig. 2 the tops of pins 3! and 32-are' below the top of rod 16, and the latter acts asaguardtoprevent the weft from falling to a low enough position to become entangled with the pins; Asshow'n herein rod l6, serving as a thread guard, is also the support for the pads, but this feature of the invention is not necessarily limited toa guard which also .acts as a mounting for the friction pads.

From the foregoing it will be seen that the invention sets forth simple means which operates to separate the tension pads at the moment in the flight of the shuttle when the pads tend to move relatively to each-other in such manner as This movement of the pads occurs when there is a change in the acceleration of the shuttle, as when the shuttle is checked, or picked. The spreader is loosely mounted for free limited movement on the shuttle lengthwise thereof and performs its spreading function due either to its momentum when the shuttle is checked, or its inertiawhen the shuttle is picked'. The springs 23 and the inclined flanges 23 and-23 cooperate with springs-2P to assist in returning the spreader to 'itsnormal position. Furthermore, the top of the thread guide rod is high enough to prevent the weft from becoming entangled with the spreader pins 3| and 32.

Having thus described the invention it will be seen that changesand modifications of the foregoing specific disclosure may-be made without departing from the-spirit and scope of the invention. 1

extending tension pads mounted on the block having adjacent vertical edges around which the pads have angular movements tending to cut the weft thread when there is an abrupt change in the acceleration of the shuttle, and spreader means mounted on the shuttle for limited free movement relatively to the pads effective incident to said abrupt'change in acceleration of the shuttle to engage and separate said pads to prevent the latter from cutting the weft thread.

2. In weft tension control means for a loom shuttle having a thread block and a thread passage therethrough, a pair of vertically extending tension pads mounted on the block to engage a weft thread passing through said passage, said pads having adjacent vertical edges around which the pads have angular movements tending to cut the weft when there is an abrupt change in the acceleration of the shuttle, and spreader means slidably mounted on the shuttle effective incident to said abrupt change in the acceleration of the shuttle to separate said pads to prevent cutting of the weft.

3. In a weft tension control for a loom shuttle having a shuttle block through which the weft passes, a pair of vertically extending tension pads movably mounted on the block and having adjacent vertical edges around which the pads have angular movements incident to an abrupt change in the acceleration of the shuttle, said angular movements tending to cause the pads to cut the weft thread, and spreader means mounted on the shuttle for movement relatively thereto and with respect to said pads and effective upon occurence of said abrupt change in the acceleration of the shuttle to effect separation of said edges and thereby prevent cutting of the weft thread.

4. In a weft tension control means for a loom shuttle having a threader block through which a weft thread passes, thread tension members normally engaging the weft and having movements relative to the block and each other incident to an abrupt change in the acceleration of the shuttle tending to cause said tension mem bers to cut the weft, and spreader means mounted on the shuttle for movement relatively thereto and with respect to said tension members acting to move the latter away from the weft thread incident to said abrupt change in the acceleration of the shuttle to prevent said tension members from cutting the weft.

5. In a weft tension control means for a loom shuttle having a threader block through which a Weft thread passes, a pair of tension members mounted on the block for relative movement with respect thereto and tending incident to an abrupt change in the acceleration of the shuttle to move in such manner as to cut the weft, and means mounted on the shuttle for free limited movement relatively thereto and with respect to said members engaging the latter incident to said abrupt change in the acceleration of the shuttle and moving said members away from the weft thread to prevent cutting thereof by the tension members.

6. In weft tension control means for a loom shuttle having a threader block formed with a thread passage through which the weft passes, a pair of weft tension pads having weft engaging surfaces held against the weft and mounted on the block for movement relatively thereto, said pads incident to an abrupt change in the acceleration of the shuttle moving relatively to the block and tending to cut the weft, a spreader plate mounted on the shuttle for limited free movement relatively thereto in the direction of the length of said passage, and spreader pins on said spreader plate spaced from each other in a direction of the length of said passage, said plate incident to said abrupt change in the acceleration of the shuttle moving one or the other of said pins, depending upon the direction of movement of the shuttle, into engagement with said pads and separating said weft engaging surfaces to prevent said pads from cutting the weft.

7. In weft tension control means for a shuttle having a threader block with a thread passage therethrough, a pair of vertically extending tension pads mounted on said block having adjacent vertical edges around which the pads have angular movements tending to cut the weft thread when the shuttle is checked at the end of a flight thereof or is picked at the start of a flight thereof, and spreader means mounted on the shuttle for limited free movement relatively to the shuttle and pads effective when the shuttle is checked at the end of a flight or is picked at the start of a flight to engage and separate said pads to prevent the latter from cutting the weft.

8. Weft tension control means for a loom shuttle having a threader block with a weft thread passage therethrough, a pair of vertically extending tension pads mounted on the block for movement relatively thereto having vertical edges around which the pads have angular movements tending to cut the weft thread due to momentum of said pads when the shuttle is checked at the end of a flight thereof, said pads tending to have said angular movements due to the inertia thereof when the shuttle is picked at the start of a flight thereof, and spreader means mounted on the shuttle for limited free movement relatively to the pads effective due to the momentum thereof when the shuttle is checked at the end of the flight thereof, and effective due to the inertia thereof when the shuttle is picked at the start of a flight thereof, to separate said pads to prevent the latter from cutting the weft thread.

9. In weft tension control means for a loom shuttle having a spreader block formed with a thread passage therethrough, weft tension members mounted on the block for movement relatively thereto tending incident to an abrupt change in the acceleration of the shuttle to move in such manner as to cut the weft, spreader means including pins for engagement with said tension members, said spreader means movable relatively to the shuttle and acting incident to said abrupt change in the acceleration of the shuttle to cause one or the other of said pins to engage and separate said tension members to prevent the latter from cutting the weft, and guard means extending across said passage above said pins to prevent the weft from having entangling engagement with said pins.

10. The weft tension control means set forth in claim 9 wherein said guard means supports said tension members.

RICHARD G. TURNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,518,696 Kaufmann Aug. 15, 1950 2,518,961 Turner Aug. 15, 1950 

